1. Field of the Invention
The present invention relates to cryosurgical probes and more particularly to a cryosurgical probe that is detachable and particularly useful with computerized tomography (CT) and other image-guided (radiological) applications.
2. Description of the Related Art
Cryosurgery involving the use of a cryosurgical probe assemblies typically involves the use of cryoprobes that are each attached to a handle that are, in turn, connected to a high-pressure fluid line with a quick-disconnect for attachment to a fluid source. There is an inherent problem with this type of system inasmuch as each cryosurgical probe assembly should be used only once due to sterilization and performance factors. Therefore, typically, the entire cryosurgical probe assembly and high-pressure fluid line must be discarded after that single use. Due to these sterilization/performance requirements there is a need to assure that the cryosurgical probe assembly may be rendered non-useable after a single-use.
Previous attempts to mitigate this problem have involved utilizing a disposable sheath over a cryosurgical probe. For example, U.S. Pat. No. 5,910,104, issued to J. D. Doback, III et al, discloses a disposable, sterilizable sheath for use on a closed loop Joule-Thomson cryosurgical probe, and the combination of the disposable sheath and the closed loop probe. The sheath is slipped over the probe, thereby separating the probe from the environment. The sheath has a grip that fits over the handle of the cryosurgical probe. The sheath has a hollow multi-lumen catheter shaped and sized to fit snugly over the cannula of the cryosurgical probe.
U.S. Pat. No. 6,306,129 B1, issued to Little et al, also discloses the use of a disposable sheath over a cryosurgical probe.
Similarly, U.S. Pat. Publication US 2002/0022832 A1, to Mikus et al, discloses a cryoprobe assembly that includes a cryoprobe and an outer sheath assembly detachably connected thereto.
Although cryosurgical probes have been very successfully used for treating prostate cancer their use has been somewhat limited for other applications such as liver, kidney, etc. because of the difficulty of imaging those body parts using ultrasound. Ultrasound is presently the preferred imaging instrumentality for prostate cryosurgery. It can be successfully used because the rectum, which is amenable to ultrasound imaging device insertion, is adjacent to the prostate. Thus, iceball formation can be effectively monitored. The liver, kidney, breast, etc. cannot be as conveniently monitored. Thus, it is desired that other imaging techniques be used. However, presently designed cryosurgical probes are not convenient with, for example, computerized tomography (CT) applications because the probe, including its handle and fluid line connection, are generally disposed along a single direction. This is problematic given the space considerations present with CT devices.
U.S. Pat. No. 5,978,697, issued to Maytal, et al, discloses an MRI-guided cryosurgical system. The Maytal system includes: (a) an MRI magnet for accommodating a patient, the MRI magnet having at least one opening for enabling access of a surgeon to the patient, the MRI magnet including at least one channel extending therethrough for receiving a line member of a surgical device; (b) a surgical device, including: (i) an operating member for operating the patient; (ii) a control member for controlling the operating member, the control member being positioned externally to the MRI room; and, (iii) a line member having a first end connectable to the operating member and a second end connectable to said control member, wherein at least a portion of the line member is received within the channel of the MRI magnet.
What is desired is a cryosurgical probe in which the operative portion of the cryosurgical probe is detachable. It is also desired that a cryosurgical probe be provided that can be used in conjunction with a variety of imaging devices.